This invention relates to a device for automatically winding sheet material and deals more particularly with a method and an apparatus wherein successive sections of a continuous length of sheet material are automatically wound into coreless tubes and are separated from the remaining sheet material length by cutting the material along regions which separate one section from the next and each tube wound by the apparatus is fastened against unravelling.
The paper winder of the invention, is useful for example in the garment industry for winding into separate tubes discrete sections of a continuous web of material, such as paper, onto which a multiplicity of markers or other graphic indicia have been created. The markers represent pattern pieces to be cut from a length of fabric and are usually rapidly drawn on the sheet material by a computer aided plotter which plots the patterns belonging to a single job in a group along a section of the web. The web material which contains these markers is of great length to accommodate the many markers that may make up a single plotting operation, each marker having a length anywhere from two to forty yards. During a plotting operation, sheet material is moved through the plotter from a supply roll across a support surface where the plot is made by an instrument, usually a pen, and is thereafter rolled onto a take-up roll. The sheet material which extends across the support surface between the supply and the take-up rolls is continuous and is entirely transferred from the supply roll to the take-up roll as a result of the successive plotting operations being conducted by the plotter on it. Thus, on a given take-up roll there may be wound sheet material of great length having a multiplicity of markers plotted on it in succession.
In the case where the plotter creates markers each associated with a separate job drawn on an associated section of the length of the web, it had been the practice of workers to manually cut the sheet material along a line corresponding to the break between one job and the beginning of the next. This was so that individual markers could be used as desired, usually by placing over a lay-up and the operator thereafter hand cutting the fabric plies along pattern lines outlined by the overlaid marker. It has been found that although the sections of the sheet material which comprised each marker could be separated by cutting them in this way, many of the cut marker sections are not necessarily immediately used. Accordingly, it is an important to somehow keep the cut sections of sheet material which may extend several tens of feet in a manageable form until such time that there is cause to use them. Also, the sheet material on the take-up roll may vary in width depending, for example, on the size of machine used to make the plot. In this way, it is further necessary to be able to convert otherwise unmanageable cut sections of sheet material into manageable form regardless of variations in the widths of the sheet material used. Additionally, it is desirable to provide a device for this purpose which is capable of being used in conjunction with a plotter or that is equally capable of functioning independently thereof. Providing a stand alone feature in such a device is desirable since it allows the plotter to be used at full capacity to conduct the next series of plotting operations on a separate roll thereby insuring efficiency of use in both machines.
Accordingly, it is an object of the present invention to provide an apparatus for winding discrete sections of a continuous length of sheet material in roll form, such that each section is cut at a transition point along its length between it and the section which follows, and is automatically wound upon itself and fastened against an unravelling.
It is another object of the present invention to provide an apparatus of the aforementioned type wherein means are provided for recognizing the transition point between discrete sections of the sheet material length and for automatically cutting the sheet material transversely of its length generally at this transition point.
It is yet a further object of the present invention to provide an apparatus of the aforementioned type which is a stand alone type capable of winding and rolling into discrete tubes sections of the sheet material initially placed on it as a continuous roll regardless of differing widths which may make up each roll.
A still further object of the present invention is to provide an apparatus of the aforementioned type wherein the effects of coning of material on a take-up roll is compensated for automatically.
A still further object of the present invention is to provide an apparatus of the aforementioned type wherein plural winding, cutting and fastening operations are capable of being conducted in succession automatically on sheet material such that the apparatus can be left essentially unattended by a user.
Yet another object is to provide a winder of the aforementioned type wherein it is capable of being used in conjunction with a plotter.
Other objects and advantages will become apparent from the following disclosure and the appendant claims.